Mechanism for driving bicycles

ABSTRACT

Improved mechanical structure for increased efficiency in the transfer of the peddling force applied to a pedal crank assembly to the rear wheel of a bicycle is disclosed. This structure increases efficiency by decreasing the loss of exerted energy when peddling at dead spots, which dead spots are the common terminology used to refer to when the legs are either at down-stroke and up-stroke positions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/986,832filed on Nov. 13, 2001, which claims the benefit of ProvisionalApplication No. 60/253,093 filed on Nov. 28, 2000.

BACKGROUND OF THE INVENTION

This invention relates to a means for increased efficiency in peddlingbicycles. Depending on the position of a cyclist's foot, differentfractions of the force exercised are conveyed to automation. It isgenerally accepted that peddling is least efficient at either theup-stroke or the down-stroke positions. This is due to the fact that thehuman leg's ability to push downward is higher than its ability to applya force in a horizontal direction. The up-stroke and the down-strokepositions of peddling are commonly referred to as dead spots. Stop andstart cranking at the dead spots will result in lower speed capabilitydue to interruption and discontinuity.

Previous efforts to solve this inefficiency include a design by Jaimesunder U.S. Pat. No. 5,911,792, issued Jun. 15, 1999 that presents anorifice located at the middle part of the cranks vertex to resolve theproblem; by Nagano, U.S. Pat. No. 5,257,562, issued November 1993,disclosing a crank bar assembly wherein the position of the connectionof the pedals to the crank bars can be shifted to-and-fro to reduceinefficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

Six drawings presented show side elevational views of different drivetrains for connecting the gears driven by the pedals and those drivingthe driven wheels, using a chain or a belt. Also two additional drawingsare presented illustrating the increased arc through which the pedalsmay be driven when driven rearwardly.

FIG. 1 shows a design in which a closed loop drive chain 168 is meshedwith and drivingly connects a pedal or drive wheel gear 156 with anauxiliary gear 158, each journalled from a bicycle frame 150 and withthe chain 168 also meshed with a driven wheel gear 162 journalled fromthe frame 150, the drive wheel gear 156 being driven in a directionopposite to the direction of rotation of the driven wheel gear 162 by ajournalled pedal crank assembly 152.

FIG. 2 shows a design in which a closed loop drive chain 126 is meshedwith a driven wheel gear 122 and with an auxiliary gear wheel 118journalled from a bicycle frame 110 and with a journalled drive or pedalgear wheel 116 also meshed with chain 126, the drive gear wheel 116 anddrive wheel 122 rotating in opposite directions.

FIG. 3 shows a design with a closed loop drive chain 58 meshed with ajournalled drive or pedal wheel gear 56 and an oppositely rotating,journalled driven wheel gear 60, the two reaches of the chain 58 beingcrossed.

FIG. 4 shows a design using an auxiliary gear 16 journalled from abicycle frame 10 and meshed with a drive or pedal gear 20 alsojournalled from frame 10. A drive gear 22 is fixed to the gear 16 androtates therewith. A drive chain 24 orbits in a direction opposite tothe direction of rotation of the pedal gear 20 and orbits and drives anassociated driven wheel (not shown) similar to driven wheel 122.

FIG. 5 shows a design using a driven wheel gear 220 meshed with anauxiliary gear 216 journalled from a bicycle frame 214 and including asecond auxiliary gear 226 fastened to auxiliary gear 216. A closed loopdrive chain 224 is trained about gear 226 and drives an associateddriven wheel 212.

FIG. 6 shows a design in which two auxiliary gears 258 and 262 arejournalled from a bicycle frame 250 and meshed together for oppositerotation. Also shown are two closed loop chains 266 and 268. The chain266 is meshed with auxiliary gear 258 and a drive or pedal wheel gear254 and the chain 268 is meshed with auxiliary gear 262 and driven wheelgear 270 to rotate driven wheel gear 270 in a direction opposite to thedirection of rotation of the pedal or drive wheel gear 254.

FIG. 7 illustrates the uppermost or down-stroke position of the peddlingfoot; and

FIG. 8 illustrates a position of the peddling foot slightly past thelowermost position of the peddling foot when peddling in acounter-clockwise direction.

SUMMARY OF THE INVENTION

The purpose of the invention claimed herein is to minimize the negativeinfluence of dead spots in cycling action.

When using a conventional bicycle and the peddling foot is at thebeginning of the down-stroke position (FIG. 7), the thigh portion of theleg is generally at a horizontal position while the calf portion of theleg is inclined backward in a generally 45° direction. At this crampedleg position, the leg's ability to apply a force in the forwarddirection is severely hampered. However, effective rearward applicationof the force in a general 45° rearward direction is efficient andproductive. Similarly, when using a conventional bicycle and thepeddling foot is at the beginning of the up-stroke position, the leg'sability to exert a force in the rearward direction past bottom deadcenter is severely hampered.

However, subject to sufficient upward and rearward displacement of theposition of the seat relative to the pedal crank assembly along a linepassing through the axis of rotation of the pedal crank assembly andinclined generally 30 degrees relative to the vertical, forwardapplication of force well past this dead spot is productive. Thus, itbecomes evident that rearward peddling for forward locomotion will beeffective in reducing the negative affects of dead spots, subject tosufficient rearward displacement of positioning of the bicycle seat froma vertical line passing through the axis of the pedal crank assembly.Driving action is interrupted in conventional bicycles when action isswitched from one leg to the other since each leg acts through an angleof less than 180°. Overlapping and uninterrupted cycling action isprovided by the bicycle disclosed and claimed herein. The bicycle of theinstant invention includes means to peddle backward for forward locationto eliminate the influence of dead spots in the cycling action. Theinnovation claimed herein provides numerous improvements compared withother resolutions of the dead spot problem, including:

-   -   1. Reduced cost of production;    -   2. Simplicity of the design with an operation requiring fewer        parts;    -   3. Less maintenance;    -   4. Lighter weight;    -   5. East of operation; and    -   6. Ease of alteration of existing bicycles.

It is noteworthy that a second advantage of the design claimed is thatrearward displacement of the bicycle seat will result in a shift ofpeddling action forward of the hip position. As a result, the need forslim bicycle seats is eliminated and the use of wide and comfortableseats for the overweight and elderly, as well as for prolonged users ismade feasible.

The principle objective of this invention is to provide a light-weightbicycle that can be comfortably ridden and driven by the operatorthereof.

Another objective of this invention is to provide a bicycle inaccordance with the preceding objectives which will conform toconventional forms of manufacture, be of simple construction, and easyto operate, so as to provide a device that will be economicallyfeasible, long lasting, and relatively trouble-free in operation.

These, together with other objectives and advantages that will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed. References toaccompanying drawings form a part thereof, with like numerals referringto like parts throughout.

DETAILED DESCRIPTION OF THE INVENTION

Referring now more specifically to the drawings, FIG. 1 shows a sideelevational view of a first form of bicycle contructed in accordancewith the present invention. Numeral 150 shows a frame of a bicycle 151with a drive or pedal wheel gear 156 supported from a pedal crankassembly 152 journalled from the frame 150 at 154. Numeral 162 refers toa rear driven wheel gear journalled from frame 150 at 166 and includinga one-way clutch structure (not shown) for driving, in the forwarddirection, a driven wheel 164 also journalled from frame 150 at 166. Anauxiliary wheel 158 is included and journalled from frame 150 at 160. Aclosed loop chain 168 is meshed with drive or pedal wheel gear 156 andwith auxiliary wheel 158. The driven wheel gear 162 is also meshed withchain 168 as shown such that peddling in rearward direction (counterclockwise) derives the bicycle 151 in the forward direction.

Attention is now directed to the second form of the invention. In FIG. 2a pedal or drive wheel gear 116 is journalled from a bicycle frame 110at 114 and a driven wheel gear 122 is journalled from frame 110 at 124.Driven wheel gear 122 includes a one-way clutch structure (not shown).An auxiliary wheel 118 is journalled from frame 110 at 120. A closedloop chain 126 is meshed with auxiliary wheel 118 and with driven wheelgear 122. The pedal or drive wheel gear 116 is meshed with chain 126 asshown such that peddling rearward (counter clockwise) drives frame 110in the forward direction, to the right.

Attention is now directed to the third form of the invention. FIG. 3shows a side elevational view of a bicycle frame 50 with a drive wheelassembly 70 including a pedal or drive wheel gear 56 and a pedal crankassembly 52 journalled from frame 50 at 54 and with a driven wheel gearassembly 60 (including a one-way clutch structure and a driven wheelgear 66) rotatably attached to frame 50 at 62. A closed loop chain 58 ismeshed with the pedal or drive wheel gear 56 in a direction opposite ofthe direction is meshed with the driven wheel gear 66 such that rotationof the pedal crank assembly 52 in an anti-clockwise direction drivesframe 50 in a forward direction (to the right). For best results thegears may either be tilted, or guiding wheels or spacers (not shown)need be provided to keep the chains in different tracts at theirjunction.

Attention is now directed to the fourth form of the invention. FIG. 4shows the side elevational view of a bicycle frame 10 with pedal crankassembly 12 and pedal or drive wheel gear 20 fastened together andjournalled from frame 10 at 14. Two auxiliary gears 16 and 22 arecoupled with each other and journalled from frame 10 at 18 with gear 16meshed with pedal wheel gear 20. A closed loop chain 24 is meshed with adriven wheel gear (not shown) and with auxiliary gear 22 as shown suchthat rearward peddling (counter clockwise) drives the frame 10 in aforward direction (to the right). It is readily visible that the twoauxiliary gears 16 and 22 could be of the same diameter in which casesaid two gears can be combined into one gear.

Attention is now directed to the fifth form of the invention. FIG. 5shows a side elevational view of a bicycle frame 214 with a driven wheelgear 220 journalled from a bicycle frame 214 at 222 and meshed with anauxiliary gear 216 coupled to a second auxiliary gear 226 and journalledfrom frame 214 at 218. A driven wheel 212 is journalled from the bicycleframe 214 at 222.

A closed loop chain 224 is meshed with auxiliary gear 226 such thatpeddling rearward (anti-clockwise) on an associated pedal crank assembly(not shown) about which the chain 224 is also meshed drives frame 214 ina forward direction (to the left). It is readily visible that the twoauxiliary gears 216 and 226 can be of the same diameter and that the twoauxiliary gears 216 and 226 can be combined into one gear.

Attention is now given to the sixth form of the invention. FIG. 6 showsthe side elevational view of a bicycle frame 250 with driven wheel 274and adjoined driven wheel gear 270 journalled from frame 250 at 272 andwith a crank assembly 252 and adjoined pedal or drive wheel gear 254journalled from frame 250 at 256. Included are two intermeshed auxiliarysprocket wheels 258 and 262 journalled from frame 250 at 264 and 260respectively. Two closed loop chains 266 and 268 are employed. The chain266 is meshed with the pedal or drive wheel gear 254 and with thesprocket wheel 258. The chain 268 is meshed with the driven wheel gear270 and the sprocket wheel 262. The sprocket wheels 258 and 262 includemeshed gears (not shown) such that the sprocket wheels 258 and 262rotate in opposite directions. Therefore, peddling backwards(anti-clockwise) drives the frame 250 in a forward direction (to theright).

FIG. (1) is further employed to illustrate attachment of a separate andsupplementary assembly 200 to an existing bicycle 151 as a means forconnecting said bicycle pedal gear 156 to the driven wheel gear 162. Theassembly 200 includes a bracket 169 to be fastened to the bicycle frameat the pivotal axis 166 of the driven wheel 164. Included is asupplementary gear 158 journalled to bracket 169 at 160. Included isalso a closed loop drive chain 168 to be meshed with supplementary gear160 and with the existing bicycle pedal gear 156 while being engagedwith the existing bicycle driven wheel gear 162 in such manner thatpeddling in rearward direction (counter clockwise) drives the bicycle inthe forward direction (to the right).

Referring to FIGS. 7 and 8, it will be noted that the seat S ispositioned appreciably above the journal axis of the drive or pedalwheel gear 156. Further, the seat S is positioned appreciably rearwardof a vertical line passing through the pedal wheel gear axis. Thearrangement shown insures that a user of the bicycle is seated in asubstantially upright position and yet physically able to “pump” thepedal crank assembly 152 with each leg through an arc substantiallygreater than 180° (at least 210+°). The active force duration in eachcycle depends on the bicycle and the physical measurements of the rider.For the seat position at angles of 30° rearward of the line of gravity(FIGS. 7 and 8) the peddling action begins shortly before the downstroke position and continues about 30° beyond the lower pedal position(FIG. 8). The result is an active force capability of about 210+° percycle.

It is now pointed out that the bicycle of the instant invention isdesigned to be ridden in a substantially upright position and with theseat positioned appreciably above and to the rear of the axis ofrotation of the pedal crank or crank bar assembly 152. This not onlykeeps the head of the rider at a high elevation for safety reasons, butalso increases the effectiveness of the reversing pedal drive train.Further, a substantially conventional bicycle frame may be modified in arelatively easy manner to be in accordance with the present invention.

It is believed evident that, as an alternative means, either chain maybe replaced by a drive belt. Further, it may be readily seen from thedrawings that the drive mechanisms of the bicycles shown are veryreliable and require very little maintenance. Further, these drivemechanisms are relatively free of operating resistance and may beconstructed of relatively light-weight materials. Therefore, thebicycles claimed may be economically produced and are operable in arelatively effortless manner.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and combinations ofdifferent designs and changes can readily occur to those skilled in theart, it is not desired to limit the invention to the exact constructionand operation shown and described; and accordingly, all suitablemodifications and equivalents that may be resorted to, should beconsidered as falling within the scope of the invention.

1. A vehicle for pedal propulsion by a passenger, said vehicle comprising: a frame; a pedal crank assembly journalled from said frame about a transverse axis, said pedal crank assembly including a pedal wheel gear; a driven wheel journalled from said frame and including at least one driven wheel gear; first and second auxiliary wheel gears journalled from said frame, said first and second auxiliary wheel gears being meshed with each other for opposite rotation; a first drive chain meshed with said first auxiliary wheel gear and with said pedal wheel gear; and a second drive chain meshed with said driven wheel gear and with said second auxiliary wheel gear, wherein the rotation of said driven wheel gear is opposite of the rotation of said pedal wheel gear.
 2. The vehicle in claim 1 wherein at least one of said first and second auxiliary wheel gears are positioned between said pedal wheel gear and said driven wheel gear.
 3. The vehicle in claim 1, further comprising: a seat mounted from said frame appreciably above and rearward of the axis of rotation of said pedal crank assembly such that a person seated on said seat in a substantially upright position may operatively engage and drive said pedal crank assembly with his or her feet.
 4. The vehicle in claim 1 wherein said at least one driven wheel gear is equipped with a one-way clutch.
 5. The vehicle in claim 1 wherein said frame is a bicycle frame.
 6. A propulsion system for a vehicle, the vehicle including a frame and a driven wheel journalled from the frame, the system comprising: a pedal crank assembly journalled from the frame about a transverse axis, said pedal crank assembly including a pedal wheel gear; at least one driven wheel gear coupled with the driven wheel; first and second auxiliary wheel gears journalled from the frame, said first and second auxiliary wheel gears being meshed with each other for opposite rotation; a first drive chain meshed with said first auxiliary wheel gear and with said pedal wheel gear; and a second drive chain meshed with said driven wheel gear and with said second auxiliary wheel gear, wherein the rotation of said driven wheel gear is opposite of the rotation of said pedal wheel gear.
 7. The system in claim 6 wherein at least one of said first and second auxiliary wheel gears are positioned between said pedal wheel gear and said driven wheel gear.
 8. The system in claim 6, further comprising: a seat mounted from the frame appreciably above and rearward of the axis of rotation of said pedal crank assembly such that a person seated on said seat in a substantially upright position may operatively engage and drive said pedal crank assembly with his or her feet.
 9. The system in claim 6 wherein said at least one driven wheel gear is equipped with a one-way clutch.
 10. The system in claim 6 wherein the frame is a bicycle frame.
 11. A propulsion system for a vehicle, the vehicle including a frame and a driven wheel journalled from the frame, the system comprising: a pedal crank assembly journalled from the frame about a transverse axis, said pedal crank assembly including a pedal wheel gear; at least one driven wheel gear coupled with the driven wheel; first and second auxiliary wheel gears journalled from the frame; means for meshing said first and second auxiliary wheel gears with each other so that said first and second auxiliary wheel gears rotate opposite to one another; means for meshing said first auxiliary wheel gear with said pedal wheel gear; and means for meshing said driven wheel gear with said second auxiliary wheel gear, wherein the rotation of said driven wheel gear is opposite of the rotation of said pedal wheel gear.
 12. The system in claim 11 wherein at least one of said first and second auxiliary wheel gears are positioned between said pedal wheel gear and said driven wheel gear.
 13. The system in claim 11, further comprising: a seat mounted from the frame appreciably above and rearward of the axis of rotation of said pedal crank assembly such that a person seated on said seat in a substantially upright position may operatively engage and drive said pedal crank assembly with his or her feet.
 14. The system in claim 11 wherein said at least one driven wheel gear is equipped with a one-way clutch.
 15. The system in claim 11 wherein the frame is a bicycle frame. 